Many hunters and sportsmen like to pursue different game which requires ammunition of different calibers. It is inconvenient and very costly to have a different rifle or firearm for each caliber of bullet used. As a result an action and receiver for a rifle was invented which would accept ammunition of different calibers. This in turn lead to the development of interchangeable rifle barrels having different caliber bores.
Currently firearms are designed with a single action and stock that will accept a variety of different barrels, however they suffer from a number of deficiencies and impracticalities which render them generally undesirable for consumers and hunters. Among such deficiencies and impracticalities are the following.
In certain rifles with interchangeable barrels, the methods of barrel attachment unduly reduce the dimensions and weaken the barrel in the chamber area, thereby limiting the range of useable cartridges and increasing the likelihood of extraction difficulties and problems in the reloading of fired cartridges.
In other firearms with interchangeable barrels, there is a problem with consistent repeatable attachment.
Another disadvantage of methods for securing a barrel to an action in interchangeable barrel rifles is that there must be some clearance between the threads of the female action and the male barrel threads, or it will be impossible to screw the action and the barrel together. A conventional side engaging set screw will always thrust the installed barrel to the other side, opposite the set screw to some degree. This results in barrel misalignment wherein the barrel will not always be in uniform coaxial alignment with the action. Many barrel threads are three-quarters of an inch or less in length. A side deflection of only 0.001 inches in a span of 0.750 inches will produce a point of impact deflection of approximately 4.8 inches at 1000 yards. Thus producing an unsatisfactory situation from an accuracy standpoint.